Color display apparatus

Abstract

A color display apparatus includes a display panel which has a light reflection area and a light transmission area for each pixel, and a light source for causing light to enter the display panel from a back surface. The light reflection area includes a first subarea in which the incident light is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable and a hue change range within which a hue of a chromatic color assumed by a reflected light is variable and a second subarea provided with a color filter in which incident light is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable. In the light transmission area, the incident light is modulated in a brightness change range within which a brightness of a transmitted light is variable. The light source is periodically switched at least between two lights different in color. The apparatus can perform the modulation in the light transmission area in synchronism with the switching in color of the light source.

1. A color display apparatus, comprising:
 a display panel which has a light reflection area and a light transmission area for each pixel, and 
 a light source for causing light to enter said display panel from a back surface of said display panel, 
 wherein the light reflection area comprises a plurality of subareas including a first subarea in which incident light is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable and a hue change range within which a hue of a chromatic color assumed by a reflected light is variable, and a second subarea provided with a color filter in which incident light is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable, 
 wherein in the light transmission area, the incident light is modulated in a brightness change range within which a brightness of a transmitted light is variable, 
 wherein said light source is periodically switched at least between two lights different in color, and 
 wherein said apparatus further comprises means for performing the modulation in the light transmission area in synchronism with the switching in color of said light source. 
 
   
   
     2. An apparatus according to  claim 1 , wherein the light transmission area is a transparent area provided with no color filter, and said light source successively and periodically emits three lights different in color each for ⅓ period of one period. 
   
   
     3. An apparatus according to  claim 1 , wherein the light transmission area comprises a transparent third subarea provided with no color filter and a fourth subarea provided with a color filter of a color identical to that of the color filter provided in the second subarea, and said light source successively emits three lights, each for ⅓ period of one period, which are different in color and includes a light passing through the color filter provided in the fourth subarea. 
   
   
     4. An apparatus according to  claim 3 , wherein the third subarea has an area equal to that of the fourth subarea. 
   
   
     5. An apparatus according to  claim 1 , wherein the first subarea is provided with a color filter of a color complementary to the color of the color filter in the second subarea, and the light transmission area comprises a third subarea provided with a color filter identical in color to the color filter in the first subarea and a fourth subarea provided with a color filter identical in color to the color filter in the second subarea. 
   
   
     6. An apparatus according to  claim 5 , wherein said light source causes light to enter said display panel so that it successively switches two lights different in color passing through the color filter in the third subarea and continuously and periodically emits a light of a single color passing through the color filter in the fourth subarea. 
   
   
     7. An apparatus according to  claim 5 , wherein said light source successively switches the at least two lights different in color in four periods including two periods in which two lights different in color pass through the color filter in the fourth subarea. 
   
   
     8. An apparatus according to  claim 5 , wherein the third subarea and the fourth subarea have an areal ratio of 2:1. 
   
   
     9. An apparatus according to  claim 5 , wherein the color of the color filter in the second subarea is green. 
   
   
     10. An apparatus according to  claim 5 , wherein said display panel is a liquid crystal display panel in which a cell thickness in the light reflection area is equal to a cell thickness in the light transmission area. 
   
   
     11. A color display apparatus, comprising:
 a display panel in which incident light is modulated and reflected or transmitted at each pixel, 
 wherein said pixel has a plurality of areas including a first area in which incident light from a front surface of said display panel is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable and a hue change range within which a hue of a chromatic color assumed by a reflected light is variable, a second area provided with a color filter in which incident light from the front surface of said display panel is modulated and reflected in a brightness change range within which a brightness of a reflected light is variable, and a third area in which incident light from a back surface is modulated and transmitted in a brightness change range within which a brightness of a transmitted light is variable to cause at least two lights different in color to successively and periodically pass through the third area. 
 
   
   
     12. An apparatus according to  claim 11 , wherein the third area is a single area through which lights of three primary colors successively and periodically pass. 
   
   
     13. An apparatus according to  claim 11 , wherein said pixel further has a fourth area with a color filter of a color identical in color to the color filter in the second area, and incident light from the back surface of said display panel is modulated in said brightness change range and transmitted to the front surface of said display panel, and wherein the third area is a single area through which two lights different in color from the color of the color filter in the fourth area successively and periodically pass.